From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from m16.mail.163.com (m16.mail.163.com [220.197.31.4]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 8B670217648; Fri, 25 Apr 2025 08:09:17 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=220.197.31.4 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1745568560; cv=none; b=Qn8yBpc5C87J/1hs9gpigIITa4a07qvVH6LtpVG2zpm6s/W5YnS2t+5rxfYUt3+xxBZwENQNMiVa7bIMvDXGYIy9js0E6nCOFDh4ilOnUQLnVKp2uLPKcBY86cqQY0cmTyY3o7tkp4kM7RcJP79ehCyvv/3elWRKtt/Fc2iG8S0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1745568560; c=relaxed/simple; bh=XQJpp88XMokP9lPGQCSmNoNIHO8Ct09S5ZSjkAs2rzI=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=KPwPURByeHpyDbJuGHDJEfUaqEtGJdny4b8cHl8F/BCSm38dGtZc18hyfuoqgc8tng92yL5D1NFPnnUzbZWZJgQRC+9ESmu4wVlBxg6uMUnEWBylfUGoGnT5Vr17pQzE/PrWsDIgmjegqjXDgAXDey9DRNxqB+INSxmphYKoCrk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=163.com; spf=pass smtp.mailfrom=163.com; dkim=pass (1024-bit key) header.d=163.com header.i=@163.com header.b=o3pmN4tg; arc=none smtp.client-ip=220.197.31.4 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=163.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=163.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=163.com header.i=@163.com header.b="o3pmN4tg" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=163.com; s=s110527; h=Message-ID:Date:MIME-Version:Subject:From: Content-Type; bh=nDI+AaMDaS6xtTgWIOFXkykW7E6eXoW4o1/iyaJzSOU=; b=o3pmN4tgS+IGXULrPBUM4uSPYaPijHid28z3EzR82jSGJwzAmIz5tCcoo6LWL6 aR7EgbWYdKwNsFwXDj1PT2Od1uUPTjVab/3azwtmUBqAKPbekl5khAkzLWMAN39t hk3SjbZbhRDavkJAfjzSdBmn5lNq4F3bnSbA7YcAJCg48= Received: from [10.42.12.155] (unknown []) by gzga-smtp-mtada-g0-2 (Coremail) with SMTP id _____wD3f1sPQwto2_WmCQ--.1960S2; Fri, 25 Apr 2025 16:08:49 +0800 (CST) Message-ID: <4c6660a6-29ce-4b97-b092-8fc15585e52a@163.com> Date: Fri, 25 Apr 2025 16:08:47 +0800 Precedence: bulk X-Mailing-List: linux-usb@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] usbip: set the dma mask to 64bit default for vhci-driver To: Christoph Hellwig , gregkh@linuxfoundation.org, Shuah Khan Cc: i@zenithal.me, linux-kernel@vger.kernel.org, linux-usb@vger.kernel.org, shuah@kernel.org, valentina.manea.m@gmail.com, Zongmin Zhou References: <3e1f8fab-0155-4ff9-800d-5fa9df88c48c@linuxfoundation.org> <20250422063409.607859-1-min_halo@163.com> Content-Language: en-US From: Zongmin Zhou In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-CM-TRANSID:_____wD3f1sPQwto2_WmCQ--.1960S2 X-Coremail-Antispam: 1Uf129KBjvdXoWrKr4rZF47tFWkKr1UCFyfJFb_yoWkCwc_uF y2qFZrJ34DArWDtayxtF93tryqvas8Wr95J3W5Kws7KasYqFyfuFn7JrWava4DXw1Syr43 Ga1Svr9Ivw1IgjkaLaAFLSUrUUUUjb8apTn2vfkv8UJUUUU8Yxn0WfASr-VFAUDa7-sFnT 9fnUUvcSsGvfC2KfnxnUUI43ZEXa7IUU6BT7UUUUU== X-CM-SenderInfo: pplqsxxdorqiywtou0bp/1tbixxg5q2gKX-B-dAABsK Dear Greg and Christoph: This patch is the simple solution for the issue described in below link: https://lore.kernel.org/all/20250219092555.112631-1-min_halo@163.com/ This issue has been discussed at length with Shuah. As Christoph said,vhci-hcd is a virtual hci, but it serves as a bridge to connect virtual USB devices to the real USB controller. Since the commit d74ffae8b8dd is applied on kernel v5.3, the virtual USB devices's max_sectors size is limited since v5.3. Just because on vhci-hcd, the dma mask setting follows the platform device default setting(32-bit). So I want to get the real USB controller dma mask to set on vhci-hcd driver， or set to 64 by default,to fix the max_sectors limited issue on virtual USB device since the commit d74ffae8b8dd applied. Thanks. On 2025/4/22 15:24, Christoph Hellwig wrote: > On Tue, Apr 22, 2025 at 02:34:09PM +0800, Zongmin Zhou wrote: >> From: Zongmin Zhou >> >> fix usb device limited max_sectors when use usbip protocol > As far as I can tell this is a virtual HCI and can't perform DMA. > Thus nothing should use DMA API calls on it and the mask is irrelevant.